Turbine engines for aircrafts are generally equipped with a means for regulating engine temperatures, such as a thermal management system (TMS), as well as a means for providing adequate ventilation to passengers of the aircraft, such as an environmental control system (ECS). As shown in the prior art embodiments of an engine 10 in FIGS. 1-3, the TMS 12 and the ECS 14 are positioned about a core engine 16 and in line with the exit stream of an associated fan section 18. The TMS 12 includes air-oil coolers (AOCs) that are configured to receive bypass airflow from the fan section 18 and direct the air through heat exchangers positioned within the passages or ducts of the AOCs. Fluid lines carrying oils and other engine fluids are routed through the heat exchangers such that as air passes through the heat exchangers and over the fluid lines, any excess heat within the fluids is dissipated into the airflow. The effectiveness of the heat exchangers is based on the surface area or the overall size of the heat exchangers, as well as the pressure differential across the heat exchangers. More recent engine fan designs tend to decrease this pressure differential, thus requiring an increase in the size of heat exchangers to compensate for the loss of cooling effectiveness. Aside from increasing the overall cost and weight of the engine, providing larger heat exchangers introduces other difficulties associated with the production, installation and maintenance of the larger heat exchangers.
A typical ECS 14 employs compressed air that is selectively obtained from a set of four bleed ports 20, two positioned at a forward portion of the high pressure compressor 22 of the engine 10 and two positioned at an aft portion of the high pressure compressor 22. Based on the mode of operation of the engine 10 and the requirements of the ECS 14, the appropriate combination of bleed ports 20 may be activated to source adequate air to a cabin of the associated aircraft via an arrangement of valves and ducts. The quantity of air sourced by the bleed ports 22, however, is generally discrete and unable to more integrally adapt to all of the conditions of the engine 10 as well as the needs of the ECS 14. More specifically, as each bleed port 22 is either completely on or completely off, the ECS 14 is unable to gradually adjust the amount of air that is sourced to accommodate for intermediary operating conditions. Furthermore, bleeding air to the ECS 14 may result in discrete drops in pressure within the high pressure compressor 22, which may further result in engine surges and inconsistent performance. Such limitations ultimately translate into substantial inefficiencies or losses of the ECS 14 as well as the overall performance of the engine 10.